Fig. 7: L-lactate increases neuronal excitability through downregulation of fAHP.

a, b Little effect of L-lactate on RMP (a) and input resistance (b). n = 15 neurons from 5 mice per group. Student’s t-test, for RMP, t₍₂₈₎ = 0.3566, p = 0.7241; for input resistance, t₍₂₈₎ = 0.313, p = 0.7566. c–e L-lactate increases neuronal excitability (c) without effect on the threshold (d) and amplitude (e) of action potential. Left, representative firing traces. Scale bars: 0.1 s, 20 mV. n = 15 neurons from 5 mice per group. For excitability, two-way ANOVA, gene effect, F_(1,196) = 65.08, p = 0.0000; for threshold, Student’s t-test, t₍₂₈₎ = 0.8113, p = 0.4241; for amplitude, t₍₂₈₎= 0.6411, p = 0.5266. f Reduced fAHP. n = 15 neurons from 5 mice per group. Left, representative firing traces. Scale bars: 10 s, 20 mV. Right, quantitative data. Student’s t-test, t₍₂₈₎= 3.882, p = 0.0006. g Representative AHP traces. Scale bars: 40 ms, 2 mV. h-i Minimal effect of L-lactate on mAHP (h) and sAHP (i). n = 11 neurons from 4 male mice per group. Student’s t-test, for mAHP, t₍₂₀₎ = 0.4404, p = 0.6644; for sAHP, Student’s t-test, t₍₂₀₎ = 0.313, p = 0.7575. j–l Diminished effect of L-lactate on fAHP (j), mAHP (k) and sAHP (l) by IbTx pretreatment. Left, representative firing traces. Scale bars: 10 s, 20 mV. n = 14 and 12 neurons from 5 mice per group. Student’s t-test, for fAHP, t₍₂₄₎ = 0.903, p = 0.3755; for mAHP, t₍₂₄₎ = 1.089, p = 0.287; for sAHP, t₍₂₄₎ = 0.1261, p = 0.9007. m Diminished effects of L-lactate on neuronal excitability by IbTx pretreatment. Left, representative firing traces. Scale bars: 0.1 s, 20 mV. Right, quantitative data. n = 14 and 12 neurons from 5 mice per group. Two-way ANOVA, gene effect, F₍₁₁₆₈₎ = 0.6741, p = 0.4128. Data were shown as mean ± SEM. ***p < 0.001; ns, no significant difference. Source data are provided as a Source Data file.